The Significance of Modulus of Elasticity and Fracture Toughness for Resine Composites

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Group 2: The significance of modulus of elasticity and fracture toughness for resin composites
Kelly Griffith, Lance Gunter, Joshua Haentges, Erik Hageman, Zohra Hasham, Nellab Hashimi

Modulus of elasticity is defined as the comparative stiffness of a material. A stiffer material will have a higher elastic modulus. Fracture toughness is the amount of stress required to propagate a preexisting flaw. It describes resistance of a material with a pre-existing flaw to fail. These two properties will be evaluated for resin composites in our paper through journal articles. Packable composites have a higher filler load and elastic modulus than flowable composites. Packing might also reduce shrinkage. Flowables have less filler and are
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Group 2: The significance of modulus of elasticity and fracture toughness for resin composites
Kelly Griffith, Lance Gunter, Joshua Haentges, Erik Hageman, Zohra Hasham, Nellab Hashimi

Modulus of elasticity is defined as the comparative stiffness of a material. A stiffer material will have a higher elastic modulus. Fracture toughness is the amount of stress required to propagate a preexisting flaw. It describes resistance of a material with a pre-existing flaw to fail. These two properties will be evaluated for resin composites in our paper through journal articles. Packable composites have a higher filler load and elastic modulus than flowable composites. Packing might also reduce shrinkage. Flowables have less filler and are used as liners and sealants. They cannot withstand much force, but this helps relieve stress due to shrinkage. However, this may be counteracted because they shrink upon curing. Flowable and packable composite resins were tested for shear strength 30 minutes, 1 day, and 1 week, after curing under constant pressure. The dimethacrylate resins tested were: Alert/- Flow It, Filtek P 60/Filtek Flow, Admira/Admira Flow—an ormocer resin—and a microfill composite resin. The resins increased in strength over one week. The packable composites were stronger than the flowables, but variable between manufacturers. The ormocer resin had a lower elastic modulus than other packable resins. Although the flowables have lower elastic moduli, they shrink more,
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